The following background description art may include insights, discoveries, understandings or disclosures, or associations together with disclosures not known to the relevant art prior to the present invention but provided by the present disclosure. Some such contributions disclosed herein may be specifically pointed out below, whereas other such contributions encompassed by the present disclosure the invention will be apparent from their context.
Frequency converters are used to change the frequency and magnitude of electricity supplied to a load. Frequency converters are being used, for example, in alternating current (AC) motor drives. In exemplary operation, a frequency converter receives AC current from an electrical power supply and converts the frequency of the received AC current to another frequency, after which the AC current is supplied to an AC electric motor. Also further parameters, for example, a voltage level of the received AC current may be changed. The AC motors are used in various applications including, for example, fans and pumps. In many applications, the use of frequency converters may provide significant energy savings compared to supplying electrical power having a constant frequency.
Programmable logic controllers (PLC) are digital computers used for automation of industrial electromechanical processes, such as control of machinery on factory assembly lines. The program for controlling the machine operation may be stored in PLC in a battery-backed-up RAM or some other non-volatile memory. However, PLC is only able to store one program at a time. Implementing PLC together with a human-machine-interface (HMI) in a frequency converter is also costly.